William s



(NO Model.)

W. S. PAOA.

SAFETY ATTACHMENT FOR ELEOTRIO MOTORS. No. 404.651. Patented June 4, 1889.

*WIT N. EIIH I I QM? am fga/ N. PETERS, mom-umo w. Wanhinglun, n. c.

UNITED STATES PATENT OFFICE.

TVILLIAM S. PACA, OF BALTIMORE, MARYLAND, ASSIGNOR OF ONE-HALF TO .IOIIA I. PAOA, OF SAME PLACE.

SAFETY ATTACHMENT FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 404,651, dated June 4, 1889.

Application filed January 11, 1889. Serial No. 296,073. (No model.)

To all whom it may concern.-

Be it known that I, IVILLIAM S. PACA, of the city of Baltimore and State of Maryland, have invented certain Improvements in Safety Attachments for Electrical Motors, of

which the following is a specification.

Electrical motors are frequently injured by the d rivin gbelt breaking or slipping from the rim of the driving-pulley, which releases it IO from its lead and allows the machine to run at an injurious rate of speed, which causes sparking of the brushes, overheating of the 'fieldanagnets, and the burning of the armature.

I 5 My invention consists in means whereby the breaking of the belt or its disarrangement with reference to the driving or the first working pulley closes a short circuit around the motor and stops the machine.

In the further description of the said invention which follows reference is made to the accompanying drawings, forming a part hereof, and in which Figure 1 is an exterior side elevation of an electrical motor connected to a pulley by means of a belt in the usual manner and provided with my improved safety apparatus. Fig. 2 is a top view of a part of the invention.

0 Similar letters of reference indicate similar parts in both the figures.

In the said drawings, A represents the fieldmagnets, and I the armature of the motor.

O is the main driving-pullcy fastened to the 3 5 armature-shaft a.

I) is the belt which connects the main driving-pulley O with the first working-pulley E.

F F are the main electrical conductors, which pass through the base G and are united with the posts 0.

II II are the short-circuit wires connected to the main electrical conductors F. These wires terminate in the springs I, fastened to the base G.

K is a bell-crank pivoted to the stand I. at

c. The lower arm (I? of the bell-crank is provided with a wedge M, adapted to fit tightly between the springs I. A spiral spring f is used to influence the wedge to assume its position between the springs I. The other arm 9 of the bell-crank F is furnished with a small roller 71, adapted to revolve about a stud j, which projects from the side of the said arm. The overhang of this roller is such as to allow it to rest on the inner surface of the driving-belt, which sustains it and its connections in an elevated position and the wedge M from contact with the spring-terminals of the short circuit wires.

Should the driving-belt break or slip from the rim of the driving-pulley or from the first working-pulley, the bell-crank falls and the wedge is forced between the spring-terminals of the shunt wires, which closes a short circuit and stops the motor.

Itwill be understood that in view of the many different ways in which the various parts of the motor and its connections can be relatively arranged to effect the result described I cannot restrict myself to the exact construction and arrangement of the cutting out mechanism shown.

I therefore claim as my invention 1. In combination with an electrical motor, a short circuit around the motor and a circuit-closcr sustained from contact with the terminals of the short-circuit wires by means of the driving -belt, substantially as specitied.

2. In combination with an electrical motor, a short circuit around the motorhaving springterminals, and a bell-crank one arm of which carries a short-circuit closer and the other a roller adapted to rest on the driving-belt, substantially as specified.

3. In combination with an electrical motor, a short circuit around the motor, and a bellcrank one arm of which carries a short-circuit closer and the other a roller adapted to rest on the driving-belt, substantially as specitied.

a. In combination with an electrical motor, a short circuit around the motor and a shortcircuit closer sustained from contact withthe said short circuit by means of aroller, which rests on the drivingbelt, substantially as specified.

5. In combination with an electrical motor, a short circuit around the motor and a pivoted arm sustained. by the driving-belt carrying a short-circuit closer, substantially as specified.

\VILLIAM S. PAUA.

\Yitnesses:

WM. T. HOWARD, DANL. FISHER. 

